JP2006220376A - Hot repairing method of lining castable refractory of refining vessel such as electric furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for repairing a castable refractory of a refining vessel such as an electric furnace or a ladle refining furnace, whereby spalling of the repaired castable refractory is dissolved and no rebound loss is produced when repairing it. <P>SOLUTION: The castable refractory in which an amount of kneaded moisture is set to 5-10% is extruded by a cylinder spindle 18 from the tip of the cylinder spindle pipe of a hydraulic cylinder in a compression molding repairing machine disposed in the refining vessel by a swing type support arm 13 to be compression molded at the defective repair part 9 of the castable refractory lining of the refining vessel 1 kept in a high temperature state after tapping molten steel, in order to repair in a hot state the defective part of the castable refractory of the refining vessel such as an electric furnace for manufacturing steel or the ladle. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to repair of an irregular refractory lined in a refining vessel such as an electric furnace for steel making or a ladle smelting furnace, and more particularly to repairing a hot smelting vessel with an irregular refractory. .

Conventionally, MgO-based or Al ₂ O ₃ -based refractories are lined in a refining vessel 1 such as an electric furnace for steel making or a ladle refining furnace. By the way, as shown in FIG. 4, in repairing the refractory melted part and spalling part generated by the use of the refining vessel 1, a high temperature state immediately after refining (this state is described in this specification). In this case, it is called “Hot”.) The amorphous refractory powder of the same material as the amorphous refractory 5 on the refractory brick 4 lined in the smelting vessel 1 is kneaded with water or a binder to form a kneaded mixture. The above-mentioned kneaded material is sprayed from the spray nozzle 22 of the irregular refractory container 21 held by the support arm 13 to the defect repairing portion 9 of the irregular refractory 5 by the compressed air supplied by the compressed air pipe 23. A repair method is generally adopted. For example, there is a method in which a refractory supply hose with a nozzle is attached to a carriage with a sliding and rotating mechanism on a swivel arm and is operated remotely (see, for example, Patent Document 1).

  However, in the conventional repair method by spraying the irregular refractory, the problem of spalling of the obtained refractory, the problem of yield reduction due to rebound loss at the time of spray, or a large repair time is required. There were various problems such as necessary problems. For example, the outline of a sprayed refractory material for hot repair of an electric furnace in a high temperature state will be described. The sprayed refractory material is generally an amorphous refractory material containing the chemical composition shown in Table 1. Used. FIG. 3 is a cross-sectional view schematically showing the configuration of the lining in a general electric furnace used in the present invention. In FIG. 3, the smelting vessel 1 has a refractory brick 4 lined on an iron shell 2 and is further not suitable. Lined with a regular refractory 4, the iron skin 2 above the molten steel 8 is cooled by a water-cooled panel 3. The refining vessel 1 has a lid 6 and an electrode 7 is mounted in the furnace. Further, the refining vessel 1 of FIGS. 2 and 4 is shown with a part of the water cooling panel 3 omitted.

  Further, the sprayed amorphous refractory material is composed of a refractory fine powder having a particle size distribution shown in Table 2, and the refractory fine powder is kneaded with water at a kneading ratio of 5 to 30% in an unshaped refractory. Consists of. Then, the sprayed refractory material kneaded with water of the irregular refractory is sprayed onto the portion of the refractory defect repairing portion 9 in the electric furnace with hot air for repair.

  By the way, generally the kneading | mixing condition of this conventional spraying refractory material was uneven. Further, since this conventional repair method is repaired by spraying, the rebound loss during hot spraying is large, and the yield is about 60 to 80%. For this reason, there was much dust scattering, and the surrounding work environment was not good.

  Furthermore, since the refractory formed by the method of spraying and repairing the refractory material sprayed onto the smelting vessel with the above-mentioned heat has a large amount of moisture contained in the irregularly shaped spray material in the kneaded state, There was a problem that the spalling resistance of the irregular refractory was much worse than that of the regular refractory such as refractory bricks.

Japanese Patent Laid-Open No. 51-151227

  The problem to be solved by the present invention is to eliminate the problem of spalling of refractory in the conventional method of repairing hot by spraying an irregular refractory with air, and further rebounding during hot spraying It is an object of the present invention to provide a method for repairing a lining refractory between hot smelting vessels such as an electric furnace or a ladle smelting furnace, which can improve the yield without loss.

  Means of the present invention for solving the above-mentioned problem is that, in the first invention, the defect part of the unshaped refractory in the refining vessel such as a steelmaking electric furnace or ladle in a high temperature state where the molten steel is discharged. In addition, the hot portion of the refractory part of the lining refractory of a refining container such as an electric furnace for steel making or ladle, in which an amorphous refractory with a water kneading amount of 5 to 10% is extruded by a hydraulic cylinder and compressed. It is a repair method.

  Furthermore, in the second invention, the extrusion of the irregular refractory by the hydraulic cylinder is performed by inserting the irregular refractory from the tip of the cylinder shaft pipe of the hydraulic cylinder of the compression molding repair machine disposed in the smelting vessel with the swing type support arm. This is a method of hot repairing a defective portion of a refractory lining of a refining vessel such as an electric furnace or ladle in the means of the present invention consisting of compression molding by extruding with a shaft.

  The operation of the above-mentioned means of the present invention will be described. In the means of the first invention, the upper limit of the water kneading ratio when kneading the amorphous refractory with water is from 30% of the conventional air blowing method. It can be as low as 10%. For this reason, the spalling resistance of the irregular refractory repaired is improved. Furthermore, in the means of the second invention, the amorphous refractory is extruded and compressed into a defective part such as a refractory melt of the amorphous refractory by the strong pressure of the hydraulic cylinder attached to the compression molding repair machine. Improved adhesion of refractories.

  The present invention relates to repairing an irregular shaped refractory lined in a refining vessel such as an electric furnace for steel making or a ladle refining furnace. Since it is a compression molding repair method, unlike the amorphous refractory consisting of uniform fine powder required by the conventional spraying repair method, the method of the present invention has an irregular shape having a particle size larger than that of coarse particles or intermediate particles. Refractories can also be used, and as a result, used old refractories discarded from electric furnaces and ladles can be recycled and used. Furthermore, since the method of the present invention is extruded by a cylinder and compression-molded, the rebound loss of the irregular refractory is greatly reduced compared to conventional spraying, the yield is improved, and the repair time can be shortened. The present invention has an excellent effect that has not been achieved so far.

  The best mode for carrying out the hot compression molding method for an amorphous refractory according to the present invention will be described with reference to the drawings. The component composition of the amorphous refractory used for compression molding in the present embodiment is the same as the component composition of the sprayed refractory material shown in Table 1 above. This is again shown in Table 3.

  Furthermore, the particle size distribution of the irregular refractory material having the composition shown in Table 3 may be the same as that shown in Table 2 above, and is larger than the sieve size of 4.76 mm and 20 mm or less. It is possible to mix and knead the material having a particle size of about 2% to 30% in the case of conventional spraying. For this reason, the refractory particles obtained by pulverizing the regular refractory discarded from the electric furnace or ladle can be recycled as an aggregate.

For example, 8% of water is added to the amorphous refractory powder, and the water and the amorphous refractory powder are supplied from the outside to the kneading machine 15 of the hot compression repair machine 10 shown in FIG. The supplied water and the irregular refractory powder are kneaded by the kneader 15. Next, the kneaded amorphous refractory 5 is supplied from the kneader 15 to the cylinder pipe 19 that houses the cylinder shaft 18 of the hydraulic cylinder 17 through the supply pipe 16, and the irregular refractory 5 to be repaired in the refining vessel 1 is repaired. The irregular refractory 5 kneaded in the defect repairing portion 9 is extruded by a cylinder shaft 18 and compression molded. The compression molding pressure by the cylinder of the hot compression molding repair machine 10 is in the range of 10 to 500 t / m ² . The hot compression repair machine 10 comprises a kneading machine 15 and a hydraulic cylinder 17 as a container of a water cooling jacket 11, and the hot compression repair machine 10 for the container comprising the water cooling jacket 11 is supported by a swing type from above and outside the refining container 1. It is supported by an arm 13 and has a counterweight 12 at the bottom to be balanced. The angle of the cylinder pipe 19 can be changed up and down at the fulcrum 20.

  Unlike the conventional spraying method, in the present invention, as shown in FIG. 2, since the compression molding is performed by the cylinder shaft 18 of the hydraulic cylinder 17, the amount of water kneading when used is 5 to 10 of the amorphous refractory 5. The upper limit can be reduced to about 1/3 as compared to about 5% to 30% in the case of conventional spraying. Further, it is not non-uniform like the conventional refractory used for spraying, but is sufficiently kneaded by the kneader 10 to be uniform. For this reason, in the method of the present invention, the rebound loss and spalling resistance of the refractory during compression molding are greatly improved as compared with the conventional spraying method. That is, the rebound loss is about 30% in the case of the conventional spraying, but is reduced to about 0% in the method of the present invention, and the spalling resistance is also about 30% as compared with the conventional spraying method. It has been improved. Furthermore, the hot repair time is shortened as shown in Table 4 below.

  Table 4 shows the repair frequency, repair time, and repair amount by comparing the hot compression molding method of the present invention with the conventional hot spraying method. As can be seen in Table 4, although the repair time for one method of the present invention is the same as that of the conventional method, the repair frequency is 1/3 to 1/5 that of the conventional method. Therefore, the total repair time can be reduced by about 60% or more compared with the conventional method.

  The hot compression molding repair machine 10 will be further described. The kneader 15 for kneading the irregular refractory 5 has a weight of about 20 tons, and the pressure of the hydraulic cylinder 17 is 10 to 500 MPa. The hot compression molding repair machine 10 is equipped with a counterweight 12 at the bottom of a container comprising a box type water cooling jacket 11. A container comprising the box-type water-cooled jacket 11 is supported from above the refining container 1 by a swing type support arm 13 or a crane (not shown), and is inserted into the hot refining container 1. Next, the tip of the cylinder shaft pipe 19 was applied to the refractory defect repairing portion 9 lined in the smelting vessel 1 and supplied from the kneaded product supply pipe 16 by the internal cylinder shaft 18 at a cylinder pressure of 10 to 500 MPa. An unshaped refractory is extruded into the defect repairing part 9 and compressed. In this case, since the weight of the hot compression molding repair machine 10 composed of the water-cooled jacket 11 is increased by the counterweight 12, the pressure is increased for compression formation.

It is typical sectional drawing of the hot compression molding repair machine used for the method of this invention. It is sectional drawing which shows typically the repair condition of the smelting container by the hot compression molding repair machine in the method of this invention. It is sectional drawing which shows typically the structure of the lining in the furnace body of an electric furnace. It is typical sectional drawing which shows repair of the refining container by the spraying of the conventional amorphous refractory.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Refining container 2 Iron skin 3 Water-cooled panel 4 Refractory brick 5 Indeterminate refractory 6 Lid 7 Electrode 8 Molten steel 9 Defect repair part 10 Hot compression repair machine 11 Water-cooling jacket 12 Counterweight 13 Swing type support arm 14 Supply pipe 15 Kneader 16 Supply Pipe 17 Hydraulic Cylinder 18 Cylinder Shaft 19 Cylinder Shaft Pipe 20 Supporting Point 21 Unshaped Refractory Container 22 Spray Nozzle 23 Pressurized Air Pipe

Claims (2)

  The irregularity of the refining vessel is characterized by extruding and compressing an irregularly shaped refractory with a water kneading amount of 5 to 10% into a defective portion of the irregularly shaped refractory in the refining vessel in a high-temperature state after steelmaking. Hot repair method for defects in standard refractories.   Extrusion of irregular refractories by hydraulic cylinders is a compression-type compression arm formed by extruding irregular refractories from the tip of the cylinder shaft pipe of a hydraulic cylinder of a compression molding repair machine placed in a refining vessel with a swing type support arm. The hot repair method of the defect | deletion part of the irregular-shaped refractory of the refining container of Claim 1 characterized by the above-mentioned.

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